Evaluate f - 9+(-2) where f = -3,005 and 9

Achemist has 200 ml of a 10% sucrose solution. she adds x ml of a 40% sucrose solution. the percent concentration, y, of the final mixture is given by the rational function: the chemist needs the concentration of the final mixture to be 30%. how many milliliters of the 40% solution should she add to the 10% solution to get this concentration?

Answer this 30 points and brainliest!

What is the length of the unknown leg in the right triangle ?